Column structures are widely used in residential and commercial buildings. They are used in exterior and interior applications and in load bearing and non-load bearing situations. The outer surface may include various forms of ornamentation and designs. Until recently, most columns used in residential construction were made from wood. But wooden columns have drawbacks. They are expensive and providing wooden columns with interesting and appealing designs makes them even more expensive.
In recent years contractors and homeowners have moved away from wooden columns in favor of molded columns. Molded columns offer numerous advantages over wooden columns such as lower costs, a variety of designs, and structural strength.
Various types of molding processes are known for making columns used in the building industry. One process is shown in U.S. Pat. No. 6,808,154, the disclosure of which is expressly incorporated herein by reference. This process utilizes a molding device having elongated inner and outer rubber molds. An elongated rigid member is extended through the inner mold. A housing is secured around the outer mold. The inner and outer rubber molds are spaced apart, and in the molding process viscous material that ultimately forms the molded part is poured downwardly between the inner and outer molds and allowed to harden and cure. After this the molded column is extracted. To remove the column, the rigid core is removed. Next, the inner mold is removed by first withdrawing the inner mold from close engagement with the column through a vacuum process and then simply pulling the inner mold from the molding device. Removing the molded column is still difficult because the outer rubber mold remains hot, or at least warm, and tends to expand between the column and the interior of the housing. This expansion tends to pinch the column, making it difficult to remove the column from the molding device, especially without damaging the outer mold or causing excessive wear on the outer mold. Indeed, this pinching effect has a detrimental effect on the life of the outer mold. Further, in cases where the outer mold forms flutes, indentions and other intricate designs in the face of the column, it is necessary to completely remove the housing, or at least portions of the housing, from the outer mold. This pinching effect, alluded to above, makes it difficult to remove the housing from the outer mold.
In the past, some of the pinching has been removed by providing the housing structure in the form of a double C-shaped housing, and decoupling or disconnecting the two C-sections prior to removing the molded column. However, in the case of a square or rectangular molding device, this only relieves the pinching on two opposed sides of the outer mold. On the other two sides, the outer mold still tends to expand outwardly and press against the interior of the adjacent housing, and this, in turn, causes the molded column to be tightly held between at least two sides of the outer mold.
Therefore, there is a need for a molding device for molding columns that will substantially eliminate this pinching effect and permit the molded column to be removed from the molding device without damaging or causing undue wear to the outer mold.